Cognitive dysfunctions after recovery from major depressive episodes.

Although recent studies have indicated that cognitive dysfunctions may persist after recovery from a major depressive episode (MDE), the claim remains controversial. To clarify this clinically important issue, we investigated the cognitive functions of people who had experienced one or more MDE, after controlling for several confounding variables: differences in (a) medications, (b) age ranges, and (c) disorder characteristics. Neuropsychological tests for memory, attention, and executive function were employed to compare 12 recovered depressed participants who had fully met the criteria for MDE to 30 participants who had partially met the criteria or had not met them at all. The recovered depressed participants were impaired on tasks of verbal learning and memory and selective or divided attention in contrast to others. After an alpha correction was applied, the deficits in divided attention remained significant. These cognitive shortfalls also distinguished people who had experienced an MDE from those who had partially experienced them or had not experienced them at all. We suggest that the experience of an MDE may have a persistent negative influence on cognitive functions, particularly on their higher levels, such as divided attention.